[Prognostic value of ophthalmic artery color Doppler sonography for progression to glaucoma in vitiligo patients]

The aim of this study was to assess the prognostic value, i.e. the role of hemodynamic changes in the ophthalmic artery determined by color Doppler imaging in patients with vitiligo in relation to the occurrence of primary open-angle glaucoma (POAG), and to call attention to the importance of examination of the vascular component in routine examinations of patients by clinical dermatologists and ophthalmologists, due to the possible correlation of vitiligo and ophthalmologic changes indicating POAG. Clinical observations and research have shown that patients treated for vitiligo are often diagnosed with POAG or have confirmed diagnosis in their medical history. These findings motivated the research of the vascular component as a possible correlation between vitiligo and POAG. The vascular component of POAG and its role in the dynamics of glaucoma progression has not been fully explained and is still somewhat controversial, and the resulting ischemic disorders are primarily related to optical nerve damage. During the course of a continuous two-year research started in March 2008 and completed in March 2010, a total of 42 patients with vitiligo were examined in the specialist dermatovenereology unit of the Department of Skin Diseases and Sexually Transmitted Diseases. Following clinical examination and Wood's lamp examination, patients with suspected glaucoma were referred to the glaucoma unit of the Department of Ophthalmology to detect or check the progression of POAG. At the Department of Internal Medicine, Split University Hospital Center, color Doppler imaging of ophthalmic artery was performed in all patients on both eyes to examine its hemodynamics. All study participants underwent complete ophthalmologic examination: visual acuity, fundus of the eye, eye pressure measurement, anterior eye segment biomicroscopy with gonioscopy and visual field. In conclusion, our study showed color Doppler imaging and investigation of vascular parameters in ophthalmic artery to provide an insight into the vascular function in differential analysis and can be determined as a correlation or potential risk factor related to vitiligo and POAG. For this reason, we suggest that patients treated for vitiligo, irrespective of their age, sex, affected area, localization and duration of the disease, should regularly undergo complete ophthalmologic examination with special emphasis on POAG diagnosis. Considering the relatively limited sample and trial period, we can already substantiate and confirm that the correlation is not random. Future research in a larger number of vitiligo and POAG patients should provide definitive answer concerning correlation between the two diseases and lead to final conclusion, along with investigation of other hematologic factors related to blood hypercoagulability in order to reach better understanding of the vascular component function.

Incidence of acute angle-closure attacks in Split-Dalmatia County, Croatia

The aim of the study was to determine the incidence of acute angle-closure attacks among residents of the Split-Dalmatia County, Croatia, during a 6-year period. In this retrospective, interventional case series study, hospital records of 53 consecutive patients (33 female, mean age 71.7 +/- 16.6 and 20 male, mean age 66.2 +/- 23.2) with acute angle-closure attacks, treated at University Department of Ophthalmology, Split University Hospital Center, Split, Croatia, from January 2002 to December 2007 were reviewed. The annual incidence of acute angle-closure attacks was 2 cases per 100,000 (95% CI, 0-3.4). The incidence of acute angle-closure was 0.6 (95% CI, 0-1.4) cases/100,000 per year. The incidence of acute angle-closure glaucoma was 1.5 (95% CI, 0-2.8) cases/100,000 per year. The incidence was 1.5 (95% CI, 0-3.4) cases/100,000 per year in males and 2.3 (95% CI, 0-4.6) in females. Nine (17%) patients were treated by medicamentous therapy, peripheral iridectomy was performed in 19 (36%) patients and laser iridotomy in 16 (30%) patients, whereas nine (17%) patients underwent filtering surgery. Median time between the onset of symptoms to presentation at the hospital was two days (range 1-21 days). There was no statistically significant association between the acute angle-closure attacks and seasonal variation (chi2-test = 4.6; p = 0.20). In conclusion, the number of patients with acute angle-closure attacks in the Split-Dalmatia County is relatively small; however, the significant incidence of acute angle-closure glaucoma could pose a social and health care problem in the County.

[The efficacy of the fixed drug combination dorzolamide 2%/timolol 0.5% in patients with primary open angle glaucoma]

The aim was to investigate the effectiveness of the fixed drug combination dorzolamide 2%/timolol 0.5% as monotherapy, substitutive and as adjunctive therapy in patients with primary open angle glaucoma. 130 patients were divided in three different study groups and treated by the combination dorzolamide 2%/timolol 0.5% as monotherapy, substitutive therapy and additional therapy. After three months using fixed combination dorzolamide 2%/timolol 0.5%, the mean IOP decreased by 5.6 mmHg. After prescribing substitutive therapy with fixed drug combination dorzolamide 2%/timolol 0.5% for 3 months, the intraocular preassure increased by 0.13 mmHg. Three months after the treatment with fixed combination dorzolamide 2%/timolol 0.5% as an additional antiglaucomatous drug, we have noticed a decrease of the mean IOP of 3.28 mmHg. Itching and soarness were reported by 43% patients. In conclusion, glaucoma drug therapy with fixed drug combination dorzolamide 2%/timolol 0.5% achieves effective lowering of intraocular preassure levels as monotherapy or as adjunctive therapy. As a substitutive therapy, the combination had the same IOP lowering effect. Simple drug administration and good drug tolerance indicate the effectiveness of the same drug.

Importance of circulating platelet aggregates and haemodynamic changes in ophthalmic artery and progression of visual field loss at pseudoexfoliation glaucoma

The aim of this work is to examine the role of circulating platelet aggregates (CPA) at pseudoexfoliation glaucoma (PXG), haemodynamic changes in the ophthalmic artery by ultrasonic color Doppler, searching for visual field progression. Vascular component at PXG and its role in VF progression dynamics has not been sufficiently explained, as well as CPA influence to ischaemic events related to optic nerve damage and VF progression. The examination included 80 patients, where of 35 (44%) men average age 68.3 +/- 7.0 and 45 (56%) women average age 65.7 +/- 7.0 (t = 1.66; p = 0.101). Forthy of them suffered from primary open angle glaucoma (POAG) as a control group (healthy), and 40 from pseudoexfoliative glaucoma (PXG) as an experimental group. All the examinees underwent complete ophthalmological examination: visual acuity, ocular fundus, intraocular pressure measured, anterior eye segment biomicroscopy with gonioscopy performed. Also VF examination was performed three times at 6 months intervals. Laboratory testing of CPA proportion values was performed by means of Wu an Hoak method and ultrasonic measurement of blood perfusion in the carotid tree, particularly concerning ophthalmic artery by means of color Doppler. Obtained decreased values of CPA proportion resulted in hypercoagulability of blood in PXG group. At PXG were also found increased blood flow resistivity indexes in ophthalmic artery (RI AO) and internal carotid artery (RI ACI), resulting with ischemia and hypoxia and finally progression of the visual filed damage. In conclusion, our study shows that examining CPA and ultrasonic monitoring of vascular parameters in ophthalmic artery with color Doppler may be the way of better understanding the vascular role in PXG prognosis.

[Comparative follow-up study of unselected male population with congenital defective color vision from inland and Mediterranean areas of Croatia]

AIM

The aim of this ten-year study (from the end of 1998 to the end of 2008) was to assess the prevalence of congenital dyschromatopsia in unselected healthy male population aged 15-45 from two Croatian regions, i.e. inland and Mediterranean parts of Croatia. Results collected in these two regions were compared and respective conclusions drawn. The results primarily referred to the prevalence of color vision disturbances and their differences according to the main color groups (dichromacy and anomalous trichromacy) and subgroups (protanopia, deuteranopia, protanomaly, deuteranomaly, and others). To our knowledge, no such a long-term study in a large population sample has been carried out in southeast Europe to date.

METHODS

Color vision was examined after complete ophthalmologic examination in all subjects presenting for examination required for amateur driver license. Color vision examination was performed by use of pseudoisochromatic Ishihara tables, Nagel II anomaloscope and Panel D-15 color test at industrial medicine offices and ophthalmology departments in the two regions. There were 12,974 and 9,974 subjects in inland and Mediterranean Croatia, respectively.

RESULTS

The results confirmed the hypothesis and clinical perception of a lower prevalence of color vision disturbances in southern parts, i.e. in Mediterranean Croatia (8.50%) as compared with inland Croatia (8.90%). The rate of dichromacy was higher in Mediterranean Croatia (2.40%), while the rate of anomalous trichromacy was greater in inland Croatia (6.93%).

CONCLUSION

The results of this study provide better insight in the status of color vision disturbances and possible differences between the relatively close areas of north (inland) and south (Mediterranean) Croatia.

[Relationship between phacoemulsification and extracapsular cataract extraction at University Department of Ophthalmology, Split University Hospital Center, during the 1997-2009 period]

The aim of the study was to show the relationship between phacoemulsification and extracapsular cataract extraction at University Department of Ophthalmology, Split University Hospital Center (assessing the length of postoperative hospital stay and postoperative visual acuity), during the 1997-2009 period. We also wanted to explore the tendency of using different types of intraocular lenses. The study was designed as a retrospective analysis of operative records. Data were collected on all patients operated for cataract at our Department during the study period. We compared the mean duration of postoperative hospital stay and mean postoperative visual acuity between 1997/1998 (more than 90% were treated with ECCE technique) and 2007/2008 (more than 90% were treated with PHACO technique). Information was also collected on the type of lenses implanted. The rate of cataract extraction by phacoemulsification was less than 10% in 1997/1998, then progressively rising to reach 99.2% in 2009. The mean hospital stay was 5.73 (range 2-19) days in 1997/1998 as compared with 1.99 (range 0.02-1) days in 2007/2008. The mean uncorrected postoperative visual acuity was 0.71 (range 0.01-1.0) in 2007/2008. In conclusion, the number of cataract patients operated on by the phacoemulsification technique progressively and significantly increased during the 1997-2009 period, confirming the method as the most acceptable and less traumatic technique that is applicable in most of cataract patients.

Vitiligo and glaucoma - an association or a coincidence? A pilot study

Our aim was to draw attention of clinicians, dermatovenereologists and ophthalmologists to the possible association of vitiligo and ocular findings characteristic of primary open angle glaucoma (POAG). According to our clinical experience, POAG is relatively often diagnosed or previously diagnosed in patients treated for vitiligo. We found no literature report directly connecting vitiligo and POAG. The articles mentioning glaucoma, i.e. increased intraocular pressure (IOP), are mainly based on secondary type of glaucoma as a direct consequence of vitiligo treated by corticosteroids. On the other hand, there is a substantial number of articles elaborating the association of vitiligo with ocular findings in known clinical syndromes. During a 2-year period, from May 2007 to May 2009, 42 patients with vitiligo were examined at University Department of Dermatology and Venereology and referred for previously appointed ophthalmologic examination at University Department of Ophthalmology, Split University Hospital Center. All patients with vitiligo underwent complete ophthalmologic examination including visual field analysis, in order to treat and follow up or diagnose newly discovered POAG. Of 42 patients with vitiligo suspect of glaucoma, POAG was confirmed in 24 (57%) patients. Age median of all vitiligo patients was 56 (range 19-82) years. In patients with vitiligo and glaucoma, the duration of vitiligo was twofold that recorded in patients with vitiligo alone, the difference being statistically significant (z=3.3; P<0.001). The risk of developing glaucoma in vitiligo patients was 4.4-fold in >56 age group versus <56 age group and 3.5-fold in patients with >13 year versus patients with <13 year duration of vitiligo. Multivariate logistic regression for glaucoma development according to vitiligo duration (< or =13 years vs. > or =13 years) and patient age (< or =56 years vs. > or =56 years) pointed to the association of glaucoma development and age and yielded a 92% probability for the association of glaucoma development and vitiligo duration. Therefore, we believe that patients treated for vitiligo should regularly undergo complete ophthalmologic examination with special attention paid to POAG irrespective of age, sex, severity, localization and duration of the disease. Although performed in a relatively small sample and over short period of time, the results of this pilot study demonstrated that this association was not accidental. Additional studies in a greater sample of vitiligo patients and POAG are expected to provide definitive answers and conclusion on the association of these two diseases.

Afect of botulinum toxin-A injection on intraocular pressure and proptosis in thyroid associated orbitopathy

The aim of this study was to evaluate the effects of extraocular muscle injection of botulinum toxin-A (BTX-A) on intraocular pressure (IOP) and proptosis in patients with ocular motility disturbances in thyroid associated orbitopathy (TAO). In 17 patients (20 eyes) with restrictive strabismus and diplopia, BTX-A injections were applied. Intraocular pressure was measured with a Goldmann applanation tonometer in primary gaze position before and 2-4 weeks after BTX-A injection. Extraorbital prominention of the eyeball was measured before and after BTX-A injection using a Hertel instrument. Before the injection, the mean IOP in primary position of gaze was 18.6 +/- 2.8 mmHg and 2-4 weeks after BTX-A injection was 16.9 +/- 3.3 mmH; (p = 0.001). There was no statistically significant difference in Hertel egzophthalmometer readings before and after BTX-A injection, 21.5 +/- 2.7 mm vs. 22.0 +/- 2.6 mm; (p = 0.678). In conclusion, BTX-A injection has a secondary lowering effect on IOP in TAO due to relaxation of extraocular muscles, but with no influence on proptosis.

The effect of travoprost 0.004% as an adjuvant to timolol 0.5% therapy

The aim of the study was to compare the efficacy of travoprost 0.004% eye drops added to therapy with timolol 0.5%. The study included 40 patients (80 eyes) with open angle glaucoma and intraocular pressure (IOP) above 18 mm Hg treated with topical beta blocker (timolol 0.50% twice a day). Travoprost 0.004% was added to timolol 0.5% therapy once daily in the evening. Follow up examinations were scheduled at 7 days, one month and three months. IOP lowering was achieved in all patients. Substantial lowering of 2.42 mm Hg was achieved after the first week of treatment. Further lowering and stabilization of IOP was recorded at three months, with total IOP decrease of 3.97 mm Hg; the difference was statistically significant (chi2=6.7743; p<0.01). At three months, target IOP was recorded in 64 eyes (16.4+/-0.7 mm Hg) and failed to be achieved in 16 eyes (21.1+/-2.3 mm Hg). Mild hyperemia was found in two patients and discrete hyperemia in 26 patients. Burning sensation associated with the use of travoprost 0.004% eye drops was reported by 68 patients. In conclusion, the use of travoprost 0.004% eye drops resulted in successful lowering of IOP and achievement of target IOP.

Progression of optic neuritis to multiple sclerosis in the County of Split-Dalmatia, Croatia

The aim of this study was to determine the incidence of monosymptomatic optic neuritis (MON) and progression of MON to multiple sclerosis (MS) from the Mediterranean region of southern Europe in the County of Split-Dalmatia, Croatia during the 11 years period from 1991 to 2001. This study was made retrospectively on the 87 cases (59 female, aged 25.9 +/- 11.3 and 28 male aged 29.9 +/- 9.2) of MON, which were treated at the Department of Ophthalmology and Department of Neurology, Split, University Hospital, from January 1991 to December 2001. In each case the diagnosis was confirmed by a chart review and cases were ascribed to the data of admittance at hospital. The annual incidence of MON was 1.9 per 100,000 (95% CI, 0.4-3.5). The incidence among males was 1.2 (95% CI, 0-2.9) cases / 100,000 per year and 2.5 (95% CI, 0.1-4.9) among females. A significant seasonal variations in the incidence of MON was not found (chi2 = 6.81, p = 0.08). MS developed in 20 of 87 patients (22.9%) and median time was 25 (SE 8) months, (95% CI, 9-41) after the MON onset. After two years 12.6% of patients with MON developed MS, 20.6% after 5 years and 22.9% after 10 years. MS was slightly but not significantly more frequent in women than in men (chi2 = 0.72, p = 0.3). In conclusion, the progression of MON to MS in the County of Split-Dalmatia, Croatia was at a relatively moderate frequency.

[Traumatic carotid-cavernous fistula]

Carotid-cavernous fistula is uncommon consequence of craniocerebral trauma. Earlier recognition of the patients with carotid-cavernous fistula and shorter time of delay in treatment could save patients from complications and vision loss. A 27-year-old man presented with severe craniocerebral injury after an car accident. He required emergent craniotomy for an open depressed cranial fractures, haemostasis and epidural hematoma. Three months later, the patient began to exhibit progressive chemosis and proptosis of left eye. Computed tomography and cerebral angiography revealed findings consistent with a carotid-cavernous fistula. Angiography revealed a fistula between carotid artery and the cavernous sinus. The patient was treated by transarterial embolization resulting in immediate and permanent occlusion of the fistula and improved visual acuity after six months follow-up. Posttraumatic carotid-cavernous fistula may be treated successfully with the use of transarterial coil embolization.

Psychosis and Wilson's disease: a case report

In this article we present a case of a 26-year-old woman with clinical picture of acute psychosis, as the first and main manifestation of Wilson's disease, who developed abnormal involuntary choreoathetoid limb movements, few days after initiation of neuroleptic therapy. At the first movement neurological symptoms were misinterpreted as side effect of haloperidol, but consulted neurologist suggested additional diagnostic procedure which confirmed Wilson's disease. Psychiatric symptomatology and abnormal involuntary movements were the clinical manifestation of this disease, which improved with neuroleptic and chelating treatment. Interdisciplinary approach with good collaboration of psychiatrists and neurologists is crucial for Wilson's disease, because early diagnosis and treatment without delay is critical to the prognosis. This case serves as a reminder that involuntary movements can be side effect of antipsychotics but also the clinical manifestation of some illnesses, for example Wilson's, Huntington's and Fuhr's diseases.

Treatment of ocular motility disturbances in Graves' disease with botulinum toxin A

The aim of this study was to evaluate the efficacy of botulinum toxin-A injections on motility disturbance in patients with dysthyroid eye disease. In 36 patients (52 orbits) with active phase of Grave's ophthalmopathy with motility disturbance, botulinum toxin-A injections were applied. Ocular motility was measured before and after treatment in four main directions (elevation, depression, abduction and adduction) with Förster perimeter. In all patients 20 units of botulinum toxin-A in one single injection was applied in the projection of the inferior rectus muscle. Statistically, the degree of upgaze increased notably in all three groups, but mostly in the first group where it amounted up to 5.8-6.0 (z = 10.0;p = 0.68). We could not prove notable increase of the motility grade in the adduction in none of the groups of the tested patients. Due to the fact that eyeball motility can be objectively measured, effect of the applied therapy can be clearly evaluated.

Pseudoexfoliation syndrome and asymptomatic myocardial dysfunction

BACKGROUND

The purpose of this study was to investigate the frequency of asymptomatic left ventricular dysfunction in patients with pseudoexfoliation syndrome.

METHODS

Two-dimensional and pulsed Doppler echocardiography of transmitral flow was performed on 27 patients with pseudoexfoliation syndrome, aged 66.9+/-5.6 years, and 24 healthy volunteers aged 63.9+/-6.5 years. Left ventricular (LV) systolic contraction and ejection were assessed by LV ejection fraction (EF) and fractional shortening (FS). LV diastolic filling parameters tested were: early fast diastolic filling (E wave), late diastolic filling (A wave), ratio E/A, velocity time integral E wave (VTIE) and A wave (VTIA), their ratio (VTIE/VTIA), pressure at the end of filling (LVEDP) and a pulmonary capillary wedge pressure (PCWP).

RESULTS

Systolic parameters EF and FS, diastolic filling parameters such as A, LVEDP and PCWP were not significantly different between patients with pseudoexfoliation syndrome and controls (P>0.05). A significant difference (P<0.05) was found with regard to the diastolic filling parameters: E (61.6+/-15.1 vs 83.7+/-21.4), ratio E/A (0.8+/-0.1 vs 1.1+/-0.2), VTIE (8.6+/-1.8 vs 9.8+/-1.9), VTIA (10.3+/-2.4 vs 7.8+/-1.6) and ratio VTIA/VTIE (1.2+/-0.2 vs 0.8+/-0.2).

CONCLUSION

Our study suggests the possibility of an association between patients with pseudoexfoliation syndrome and a discrete asymptomatic myocardial diastolic dysfunction.

[Cyclocryocoagulation in treatment of neovascular glaucoma]

Neovascular glaucoma (NVG) is a pathological condition of the eye with fast deterioration, accompanied with eyeball pain and loosing sight. The aim of the study was to examine the efficacy of cryotherapy in the treatment of NVG which is resistant to medical and surgical therapy, concerning intraocular pressure (IOT) and eyeball pain immediately after the treatment and 6 months after. In the Department of Ophthalmology, Split University Scool of Medicine, during three years 70 patients with NVG, which were resistant to medical and surgical treatment, were included in the prospective study. There were 50 males and 21 women, average age 74 +/- 6.94 (45-87). The patients were treated with transconjuctival cyclocryocoagulation, machine ERBOKRYIO AE-ERBE was used. The average value of IOT was: at admission 44.8 mmHg, 7 days after the treatment 30.7 mmHg with the tendency of falling down 30 and 90 days later, to finally 19.9 mmHg 180 days after the treatment. The IOT was significantly lower after the treatment. At admission, the average value of eyeball pain intensity was high (4.2), 7 days after the treatment it was 2.1 with the tendency of falling down to finally 1.1 180 days after the treatment. The eyeball pain intensity was significantly lower after the treatment. Cyclocryocoagulation is a method of choice in the treatment of NVG resistant to medical and surgical treatment. Cyclocryocoagulation, as a treatment of noncontrolled progressive NVG, does not have any effect on the improvement of sight in these patient.

Epidemiology of adult eye injuries in Split-Dalmatian county

AIM

To determine the incidence of eye injuries, population groups at risk, circumstances and activities at the time of accident, causes, mechanism, type and severity of injury, therapeutic procedures, final outcome, and the incidence of blindness in patients over 18 years of age.

METHODS

We retrospectively analyzed data on 383 patients with eye injuries (397 eyes) hospitalized at Split University Hospital, Department of Ophthalmology, between January 1998 and December 2002. Standardized international classification of ocular trauma (Birmingham Eye Trauma Terminology) and eye injury score were used for eye injury categorization.

RESULTS

The incidence of ocular injuries requiring hospitalization in Split-Dalmatian County was 23.9 per 100,000 population and the incidence of monocular blindness caused by injuries was 4.1 per 100,000 population. The male to female ratio was 5.4 to 1. Forty-one percent of injuries occurred at home, 27.7% at work, 13.8% in agriculture, 7.0% during assault or scuffle, 5.2% in traffic, 3.7% during sports activities, and 1.6% at school. Among 397 injuries, 86.4% were mechanical and 13.6% chemical. Out of 343 mechanical injuries, 67.3% were closed globe and 32.7% were open globe injuries. The most frequent objects causing mechanical injuries were tree branch or wood (15.9%) causing 26.3% of ruptures and 21.4% of contusions; pieces of metal or stone (13.9%) causing 80.8% of intraocular foreign body lacerations; and nails, wire, or scissors (8.8%) causing 26.7% of lamellar and 23.9% of penetrating lacerations. Closed globe injuries were less severe and had better final visual outcome than open globe injuries. Final visual acuity was 0.4 or better in 91.4% of mild vs 13.9% of severe injuries. Injuries resulted in monocular blindness (visual acuity <0.1) in 71 (17.9%) patients: 35.2% were due to penetrating lacerations, 23.9% to ruptures, 21.1% to contusions, 16.9% to intraocular foreign body lacerations, and 1.4% due to burns as well as lamellar lacerations.

CONCLUSION

There was a high incidence of ocular trauma and consequent blindness in Split-Dalmatian County. For the prevention of serious eye injuries, health education and safety strategies should be applied both at home and place of work, where blinding injuries most often occur.

The incidence of optic neuritis in Split-Dalmatia county, Croatia

The aim of the study was to determine the incidence of monosymptomatic optic neuritis (MON) in residents of Split-Dalmatia County, Croatia. The 127 cases (83 female, aged 26.2+/-9.9 and 44 male aged 26.9+/-11.2) with MON presented between January 1985 and December 2001 were analyzed from hospital data. The annual incidence was 1.6 per 100,000 (95% CI, 0-3). The incidence among females was 2.2 (95% CI, 0-4.6) cases / 100,000 per year and 1.1 (95% CI, 0-3) among males. The difference in incidence rates for women vs. men was not significant (chi2=0.41; p=0.52), although it is more likely that a true difference exists. The peak incidence in both sexes observed in the group 20-29 years of age was 4.2 (95% CI, 0-10). The highest incidence of MON was found in spring (46 cases). In summary, the incidence of MON in Split-Dalmatia County during the 17 years period is relatively low.

[Disorders of color vision]

This review gives a summary of all colour vision disorders (dyschromatopsias) and diagnostic methods and tests. Colour vision is inadequately treated in current literature with regard to the choice of diagnostic methods and the interpretation of results for a single disorder, which contributes to wrong dyschromatopsia diagnosing seen every day in specialist practice. Examination for colour disorders is usually outpatient and is carried out by ophthalmology or neurology departments or occupational health services under the supervision of an ophthalmologist to prevent misinterpretation of results and wrong occupational choices. The problem is very serious, and proper education should be able to provide guidelines for correct and early diagnosis of dyschromatopsia. As the examination is not well defined, it is very important to set unique criteria in diagnosing any single colour vision disorder.

Frequency of congenital dyschromatopsias in male population of the Split-Dalmatian County in Croatia

A population of 9974 healthy male subjects (aged 15-45 years) was screened for congenital dyschromatopsia. The study group consisted of subjects applying for a driving license in the Split-Dalmatian County between 1996 and 1999. The aim was to establish colour vision deficiency (dichromats) and borderline deficiencies (anomalous trichromats) in candidates through complete ophthalmologic examination including the Ishihara pseudoisocromatic plates, anomaloscope Nagel II, and Hue Lanthony colour test. The frequency of congenital dyschromatopsias was 8.48%. This frequency includes 2.39% dichromats (1.49% protanops and 0.90% deuteranopes) and 6.09% anomalous trichromats (1.27% protanomals, 4.20% deuteranomals, 0.21% extreme protanomals and 0.41% extreme deuteranomals). It is important to recognise and classify dyschromatopsias according to type and severity in order to avoid misinterpretation of results and consequent unjustified limitations imposed on anomalous trichromats in the selection of a profession.